When I discuss a low-carbon economy and a transition of our energy system with experts around the world, it is clear that many key questions remain unanswered. There are challenges around commercials, technology, politics or behaviour. However, there are even bigger challenges, if we don’t solve those: living on a planet with a 4-6 degree higher temperature. So, we have to choose, which problem we really want to solve.

Some of the questions around a low-carbon economy relate to technology and markets. For instance, if we had lot’s of electric vehicles but make our electricity from coal – how does that help? Is the cost of renewables, of storage or of carbon capture not too high, still? How do we deal with the intermittency of wind and solar power? How much fluctuation can our grids handle, while still reliably supplying power? What are the risks of geo-engineering?

Or the questions might be about our behavior: why is there such a striking disconnect between our values and our everyday behavior, when it comes to carbon emissions? Do we really fly less, eat less meat, or use public transport more often just to reduce global warming? Do we even bother to exchange our light bulbs, insulate our windows or make informed purchasing decisions on everyday products? Is it meaningless, what we, as individuals, do about a problem of such vast proportions? And don’t many of us still see climate change as a far-away and abstract phenomenon, almost too complex to grasp and too disturbing to ponder – when in reality, it is already affecting our lives, everyday, around the world?

Or the questions might relate to politics and economics: will politicians (and their voters) ever agree on global emissions rules and on national carbon budgets? Are we doomed to live out the “tragedy of the commons”, because we are simply not made to cooperate with one another? And what about the poor countries’ rights to cheap energy for development? If they go on a low-carbon growth plan, will their development be stymied (note: I don’t think so)? And who would pay for this?

There are many more questions about our ability to create a global, low-carbon economy – and that is not surprising, since it would require remodeling our way of life significantly and at a global scale, something humanity has never consciously done before in its history. Yet, it is a fact of our time that we have to tackle this. For the alternative, living on a hotter planet, will pose much (!) more challenging problems.

So this is our choice: Act now to solve very tough problems or react (not much) later to tackle much tougher problems in a radically less comfortable environment.

And it’s not like we can’t solve big, complex problems. Our age is more dynamic and technology-enabled than any before. We can do more than ever before – for better or worse. Also, we have demonstrated, that we can achieve goals that might seem unrealistic at first. Just think of the mission to the moon. Or think of our success in almost eradicating global diseases such as polio or smallpox. In terms of the environment, we have also achieved a lot: Regionally, waterbodies and the air has been cleaned up in many locations. Globally, the Montreal Protocol, limiting the use of substances that deplete the earth’s ozone layer, is an example of successful international regulatory cooperation.

Yes, it’s not easy to change to a low-carbon economy. And yes, there are questions that cannot yet be answered in full and there are tough nuts to crack. But equally, there is nothing to suggest that we cannot solve the problems. This is the good news: there are no logical or physical barriers. It is merely a question of will and ingenuity. Since making this transition is critical to our survival, I would rather tackle these problems than the much tougher ones that come with living on a hot planet.